1. Field
This invention relates to structures for interconnecting two or more structural elements. More particularly, the invention is directed to structures for interconnecting tubular or open channel elements one to another.
2. State of the Art
Various structures are found by the interconnection of tubular elements in preselected arrangements. The connections of one tubular element to another tubular element present several structural problems. Traditionally, in the instance of tubular elements formed of metal, welding has been a common means of securing one element to another. While welding can produce a strong joint between the elements, in these instances where the joint is exposed to the elements, welded joints are subject to rust and erioration. Should the user wish to undo the connection between the elements, a welded joint can prove difficult to undo. Further, should these tubular elements be galvanized, then galvanized coating must be removed from the joint location in order to facilitate the formation of the welded joint. This removal of galvanized coating subjects the affected areas to the possibility of rusting.
Interconnection structures find various applications in commercial, industrial as well as residential environments. One application of such elements is in the fabrication of gate structures for fencing. Gates typically include a frame structure which is traditionally polygonal in configuration, e.g., rectangular. Gate frame structures may be constructed by joining four or more elongate linear elements to one another at their respective ends to form a polygonally configured structure. If the fencing arrangement in question is constructed of vinyl, the gate frame is oftentimes fabricated of metal tubing and a sheath of vinyl is positioned overtop the frame to render the gate compatible with the remaining structure of the fence. Manufacturers of such gate frames have historically experienced difficulties in joining the various tubular elements together in a way which provides sufficient structural integrity while simultaneously ensuring adequate protection against rust and other forms of erioration from exposure to the elements. Representative efforts in this regard are illustrated in U.S. Pat. No. 5,868,382, U.S. Pat. No. 4,793,098; U.S. Pat. No. 3,395,489; U.S. Pat. No. 4,628,635; U.S. Pat. No. 4,796,384; U.S. Pat. No. 4,813,182; U.S. Pat. No. 5,457,914; U.S. Pat. No. 5,556,080; U.S. Pat. No. 5,702,090; U.S. Pat. No. 5,716,041; and U.S. Pat. No. 5,771,505. While many of these prior constructions address some of the traditional concerns regarding gate constructions, these constructions have yet to meet all of the concerns raised by manufacturers, installers and consumers of such gate products.
FIG. 1 illustrates a conventional interconnection structure. As shown, a first upright A has an extension B welded thereto to extend orthogonally outwardly from the upright A. The extension B is dimensioned to be received within a tubular member D. The tubular member D is dimensioned to be received within a vinyl sheath E. Upon the tubular member D being aligned with the extension B and the sheath E being aligned with the extension B and the tubular member D, the fabricator drills a hole through all three members thereby forming apertures C, H and G. The apertures are dimensioned to receive and retain a rivet F. With the aperture G being aligned with the apertures H and C, the rivet F is inserted through the sheath, tubular member D and the extension B to lock all of the three members into an association one with another.
This particular construction has several problems associated with it. First, to obtain a weld securing the extension B to the upright A is difficult in practice. Further, such a weld is subject to rust. Even assuming that the upright A and the extension B are fabricated from galvanized metal, the galvanizing coating must be removed into order to permit the formation of a welded joint. The removal of the galvanized coating creates the possibility of rust formation. When extensions B are welded to each end of the upright A, the length of upright A is fixed. In many circumstances, the length of the upright A is required to be adjusted for length in the field. The use of welding to affix the extensions B to the upright render such adjustments difficult if not impossible one the weld has been made.
Secondly, the drilling of apertures C, H and G exposes portions of the otherwise galvanized extension and tubular member to rust, i.e. about the edges of the apertures. Further, the use of the extension B requires the sheathing J, which is intended to cover the upright A, to be split longitudinally along its length in order to accommodate the extension B. Furthermore, an opening K must be defined within the sheath J to accommodate the extension B. It follows that not only is sheathing J difficult to manufacture, but furthermore, it is difficult to install.
There continues to exist a need for an interconnection structure and specifically an interconnection structure suitable for gate frame construction which at once provides a high degree of structural integrity and a capacity for length adjustment of the tubular elements in the field while simultaneously providing a high resistance to rust or other forms of erioration resultant from exposure of the interconnection structure to the elements.